#include <iostream>
#include <vector>
#include <cmath>
#include <string>
#include <map>
#include <set>

using namespace std;

int main()
{
    int n, k;
    cin >> n;
    set<int> student;
    for (int i = 0; i < n; i++)
    {
        int datest;
        cin >> datest;
        student.insert(datest);
    }
    cin >> k;
    int j = 0;
    for (int i = 0; i < k; i++)
    {
        int datech;
        cin >> datech;
        if (student.find(datech) != student.end())
        {
            j += 1;
        }
    }
    cout << j << endl;
    return 0;
}